Sharing system users for related services

[raingloom]

I'm packaging the Molly Brown Gemini server and I'm trying to play nice
with the already packaged gmnisrv.
Should the two use the same service name and system users? Most users
probably won't want to run both servers at the same time, so the former
seems like a good idea. And the latter would be preferable because if
they use the same certs, %gmnisrv-activation will trample over the
permissions when they do want to run both for some reason.

So should I just reuse %gmnisrv-accounts or should they both use a
shared %gemini-server-accounts?